gluPartialDisk.3gl




Name

  gluPartialDisk - draw	an arc of a disk


C Specification

  void gluPartialDisk( GLUquadricObj *qobj,
		       GLdouble	innerRadius,
		       GLdouble	outerRadius,
		       GLint slices,
		       GLint loops,
		       GLdouble	startAngle,
		       GLdouble	sweepAngle )


Parameters


  qobj	       Specifies a quadrics object (created with gluNewQuadric).

  innerRadius  Specifies the inner radius of the partial disk (can be zero).

  outerRadius  Specifies the outer radius of the partial disk.

  slices       Specfies	the number of subdivisions around the z	axis.

  loops	       Specifies the number of concentric rings	about the origin into
	       which the partial disk is subdivided.

  startAngle   Specifies the starting angle, in	degrees, of the	disk portion.

  sweepAngle   Specifies the sweep angle, in degrees, of the disk portion.


Description

  gluPartialDisk renders a partial disk	on the z=0 plane.  A partial disk is
  similar to a full disk, except that only the subset of the disk from
  startAngle through startAngle	+ sweepAngle is	included (where	0 degrees is
  along	the +y axis, 90	degrees	along the +x axis, 180 along the -y axis, and
  270 along the	-x axis).

  The partial disk has a radius	of outerRadius,	and contains a concentric
  circular hole	with a radius of innerRadius.  If innerRadius is zero, then
  no hole is generated.	 The partial disk is subdivided	around the z axis
  into slices (like pizza slices), and also about the z	axis into rings	(as
  specified by slices and loops, respectively).

  With respect to orientation, the +z side of the partial disk is considered
  to be	outside	(see gluQuadricOrientation). This means	that if	the
  orientation is set to	GLU_OUTSIDE, then any normals generated	point along
  the +z axis.	Otherwise, they	point along the	-z axis.

  If texturing is turned on (with gluQuadricTexture), texture coordinates are
  generated linearly such that where r=outerRadius, the	value at (r, 0,	0) is
  (1, 0.5), at (0, r, 0) it is (0.5, 1), at (-r, 0, 0) it is (0, 0.5), and at
  (0, -r, 0) it	is (0.5, 0).



See Also

  gluCylinder, gluDisk,	gluNewQuadric, gluQuadricOrientation,
  gluQuadricTexture, gluSphere




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Last Edited: Mon, May 22, 1995

AFV